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Case Scenario 1: Anterior Circulation Stroke Assessments

Rhonda Whiteman, R.N., MN, CNN (C)

Clinical Nurse Specialist

Central South Regional Stroke Network

September 14, 2023

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Objectives

To review clinical presentations of the common ischemic stroke syndromes

To discuss key assessments for patients with anterior circulation strokes:

Stroke Symptom Onset/Last Known Well
Speech Assessments
Motor Assessment
Neglect
Visual Disturbance Field Deficit

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Case 1

A 56 year old female was observed by her husband to collapse while eating dinner. When he went over to assist her, she could not speak, had a right sided facial droop and she could not move her right arm or leg

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NEUROANATOMY REVIEW/�STROKE SYNDROMES

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Cerebral Circulation

The brain has higher requirements for oxygen and glucose than other organs.

Approximately 20% of resting cardiac output is supplied to the brain at a rate of 800 – 1000 ml of cerebral blood flow per minute.

Brain derives its arterial supply from a pair of carotid arteries which supplies the anterior circulation and 2 vertebral arteries which provides the posterior circulation

Anterior Circulation: Internal carotid arteries and it’s branches which supply anterior 2/3 of cerebral hemispheres

Left Internal Carotid originates from the aorta – the Right Internal Carotid originates from the innominate artery of the aorta

Before enter brain give rise to :

Tympanic and Ophthalmic arteries

After both enter the brain the Internal Carotids branch off into:

Anterior Cerebral Artery

Middle Cerebral Artery

Posterior Communicating Artery

Posterior Circulation is made up of the Vertebral artery and its branches.

Vertebral and basilar arteries supply posterior and medial regions of hemispheres, brainstem, diencephalon, cerebellum and cervical spinal cord

The Vertebral Arteries originate off subclavian artery and enter brain through foramen magnum

Vertebral Arteries unite at the pons to become Basilar Artery

Basilar Artery divides to 2 Posterior Cerebral Arteries

Cerebral Circulation is Tightly regulated to meet metabolic demands in healthy patients. However, the ability of the brain to autoregulate is lost if the brain is damaged. Decreased cerebral blood flow can lead it ischemic, infarction and cerebral edema

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Key Functional Areas of the Brain

The brain is made of 3 parts: cerebral cortex, brainstem and cerebellum.

Cerebral Cortex:

Frontal lobe is the largest in the brain making up 60% of the cerebrum.

It is composed of 3 main functional areas:

Prefrontal area: focuses on concentration, abstraction, memory, judgment, insight, emotion, tact and inhibition, sequences thoughts appropriately and evaluates the consequences of actions and solves intellectual functions, guides behaviours in accordance with societal laws/morals.

Broca’s area – Expressive Speech - speech expression, word formation, articulation, pronunciation, voice and speech production

Motor Cortex – it is arranged somatopically so that so that certain areas of the region control specific areas of the contralateral body.

The parietal lobe controls sensation on the opposite of the body.

The sensory cortex is arranged in a topographical scheme as the motor strip. It controls the integration of sensory information among various modalities , including point discrimination, pressure, texture, body interpretation and orientation, pain and proprioreception, visual spatial information in the non dominant hemisphere.

The major sensory inputs from the skin (touch, temperature, and pain receptors) relay through the thalamus to the parietal lobe

Sensory Cortex is arranged in the same type of topographical scheme as the motor strip

Injury to this part of the brain in the non dominant hemisphere may result in neglect of a part of the body. Sometimes patients with injury to this area are sitting on their arm, arm may have fallen off the wheel chair because they are unaware of it, they may try to get out of bed as they are unaware of their deficits,

The temporal lobe is the primary auditory and associational areas.

Primary Auditory Area – to receive and discriminate sounds and interpret sounds

Wernickes area - which spans the region between temporal and parietal lobes, plays a key role (in tandem with Broca's area in the frontal lobe) in speech comprehension.

– comprehension of language

Integration of somatic, auditory and visual association

Detailed memory

Occipital Lobe: Primary visual receptive and association areas of the brain. Spatial organization of vision, sharp borders, colours and contrasts, visual interpretation

Brainstem is made up of the midbrain, pons and medulla.

The brainstem plays an important role in the regulation of cardiac and respiratory function. It also regulates the central nervous system, and is pivotal in maintaining consciousness and regulating the sleep cycle. The brainstem has many basic functions including heart rate, breathing, sleeping, and eating. The Brainstem houses all of the cranial nerves.

Responsible for transmission of information from the cerebral cortex to the brainstem and cerebellum. All of the sensory pathways pass through the brainstem,

Reticular activating system-level at the midbrain which helps with level of arousal – level of consciousness, alertness

ItMaintains equilibrium and balance, coordinates automatic movement and regulates muscle tone

Receives sensory input from the spinal cord and brain and coordinates this into fine, precision movement.

Damage to the cerebellum produces disturbances in fine movement, equilibrium,

posture and motor learning.

is separated from the cerebral cortex by a layer of dura matter.

Think about DWI Roadside test as representative of problems with cerebellum.
If you follow the same test with patients they cannot perform finger to nose, walk
straight line and have an ataxic stagger gait

This pictorial review the location of key functions of the brain:

motor cortex,
sensory cortex,
speech,
language,
hearing,
vision,
emotions,
balance,
coordination

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Middle Cerebral Artery (MCA) Stroke

Hemiplegia (Face, arm, leg)
Sensory deficits
Homonymous Hemianopsia
Aphasia
Confusion
Neglect
Headache

www.strokecentre.org

The middle cerebral artery strokes account for about 2/3 of all ischemic strokes

Middle cerebral artery supplies blood to the lateral aspects of frontal, parietal, temporal lobe and occipital lobe

Patients will present with variable weakness of the face arm and leg

Sensory loss is in a pattern similar to that of the motor deficit

Patient will have homonymous hemianopia

Dysarthria

Aphasia which may be broca or Wernicke’s aphasia

Patient will have apraxia – loss of the ability to execute or carry out movements despite possibly have the ability to perform them

Alexia or inability read or comprehend speech

Agraphia – inability or loss of ability to communicate through writing

Acalculia – inability to perform arithmetic operation

In our case the stroke is in the left hemisphere but if the stroke was a right MCA stroke – they would have the similar motor, sensory and visual losses but would also have neglect

Anosognosia – Lack of insight – inability to perceive their illness.

Asomatognosia – lack of body awareness – this is that the patient does not understand where limb is so if the patient has an hemiplegic shoulder could be lying on it, be up in the wheelchair and her arm falls of the arm board and is dangling but the patient is unaware

This patient requires all disciplines to work together to support recovery of this patient

Areas of focus are:

mobility, improving functional recovery of arm and leg, Hemi arm protocol to prevent shoulder injury,
improve ADL’s and manage visual neglect and hemianopia,
Dysphagia and communication
Due to the neglect and body sense awareness – they may only look to one side, only wash one side of their body, only eat from one side of their tray – it is important to approach from that side to encourage the patient to look to that side, have them scan to the opposite visual field, etc.
Patients with injury to the right hemisphere can be at significant risk for injury due to the neglect and anosognosia as they may be at risk for falls as they may try to get out of bed as they are not aware of the significant weakness on that side, may not see things in their visual field, may bump into walls when in a wheel chair.

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Anterior Cerebral Artery (ACA) Stroke

Paralysis of the lower leg
Impaired Gait
Sensory loss to toes, foot and leg
Flat Affect
Lack of Initiation, apathy
Executive Dysfunction
Incontinence

www.strokecentre.org

The anterior cerebral artery supplies the superior and medial part of the parietal lobe and the midline of the frontal lobe.

It is not an common type of stroke accounting for approximately 1 - 4% of stroke.

If you think back to the motor and sensory homunculus earlier as the anterior cerebral artery covers the medial aspects of the frontal and parietal lobes it is only the leg that experiences sensory and motor loss

The Anterior Cerebral Artery supplies the Prefrontal cortex which results in Apathy or lack of initiation, agitation, memory impairments, emotional ability and are common impairments due the impact of the prefrontal lobe.

The impact of these deficits can result in patient who functionally could feed, bath themselves who will sit and look at their tray and bath basin despite being able to do the task. You may need to provide encouragement or supervision to have the patient complete the task. The patient might also refuse to sit in the chair or participate in rehabilitation due the impaired ability to initiate the task. The patient requires significant encouragement and motivation to participate in tasks.

The emotional lability or lack of impulse control can create situations where the patient is not themselves. They may be sexually or verbally inappropriate in their speech or actions. This can be challenging and upsetting for families.

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Lacunar Strokes

25% of all ischemic strokes
Occlusion of perforating arteries of intracranial arteries
Hypertension (68%) and diabetes (30%)
23 - 41% of patients will exhibit neurological deterioration after symptom onset
5 Lacunar Syndromes

www.strokecentre.org

Lacunar Stroke are a marker of cerebral small vessel disease and account for up to 25% of all ischemic stroke

Caused by a microatheroma and thrombosis of small penetrating or perforating arteries of the intracranial arteries

Predominantly in the basal ganglia, putamen, thalamus

Blood vessel - lentriculostriate branches of the Anterior Cerebral Artery and Middle Cerebral Artery

Lacunar comes from the Latin word meaning hole and is used to describe the Post-healing process ‘lacunae lakes’ or small cavities remain

Risk factors for lacunar stroke, uncontrolled hypertension (most common at 68%), diabetes (30%),. Advanced age, smoking and hyperlipidemia

23 – 41% of patients with lacunar strokes exhibit deterioration after symptom onset. Those who deteriorate have increased chance of having a poor functional outcomes

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Lacunar Stroke Syndromes

Type of Lacunar Stroke	Where is affected?	Patient Presentation
Pure Motor Stroke	Infarction of Posterior Limb of the Internal Capsule	Course is often stuttering over hours to days Contralateral hemiparesis of face, arm and leg, dysarthria
Pure Sensory Stroke	Thalamic Infarction	Contralateral sensory loss to all modalities that usually affect the: Face, upper and lower extremities Impairment of pain, temperature touch, position and vibration

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Lacunar Stroke Syndromes

Type of Lacunar Stroke	Where is affected?	Patient Presentation
Ataxic Hemiparesis	Infarct affecting the corona radiate	Ipsilateral paresis of leg Arm and Leg ataxia
Dysarthria & Clumsy Hand	Infarct in pons, corona radiate and internal capsule	Facial weakness with Dysarthria and Dysphagia Weakness of hand, impaired manual dexterity and ataxia Sometimes weakness in arm or leg
Sensorimotor Stroke	Infarct at the junction between the thalamus and internal capsule	Weakness and sensory loss with no visual field deficit, aphasia, neglect or other symptoms

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Posterior Cerebral Artery (PCA) Stroke

Incidence 5 to 10%

Common PCA Strokes involve:

Occipital Lobe
Medial Temporal Lobe
Thalamus
Upper Brainstem and Midbrain

www.strokecentre.org

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LAST KNOWN WELL/�STROKE SYMPTOMS ONSET

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Last Known Well/�Stroke Symptom Onset

Critical piece of information

Witness onset of symptoms is easy – confirm

Stroke Symptom Onset with witness

If stroke symptoms were not witnessed,

the onset of symptoms is based on

the “Last known well

Stroke Thrombolysis has strict has criteria for �administration based on �onset time within 4.5 hours

Endovascular treatment is an �option for selected stroke patients �up to 24 hours

Onset of symptoms is a critical piece of information.

If stroke symptoms are not witnessed, the onset of symptoms is based on the last known well.

-last seen normal is when was the patient last seen without stroke symptoms or was at normal baseline health. It is not the time the patient was found with stroke symptoms.

It seems like a simple concept but I can tell you it can be one of the hardest thing to determine.

If I woke up with symptoms – it would be when the I went to bed if I was observed to be at my normal state of health when I went to bed not when I woke up with symptoms. - It maybe when the patient went to sleep at night and identified when the patient wakes up in the morning.

tPA can be given up to 4.5 hrs since last seen normal.

- Endovascular Therapy can be performed up to 24 hours

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How to Assess?

When you last see the patient?
When did you last talk to them?
What were they doing last?
What do they normally do at that time of day? Before or after that time?
Did you notice anything to indicate they were doing their normal routine?

If the person woke up with symptoms:

Did they get up over night?
Were they at their normal baseline health when they got up?
Did you see them before they went to bed – were they in their normal state of health?
Did you see them when they got up?

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WHAT ARE SOME KEY QUESTIONS YOU FIND HELPFUL IN DETERMINE LAST KNOWN WELL?

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ANTERIOR CIRCULATION �STROKE ASSESSMENT

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SPEECH ASSESSMENT�RECEPTIVE AND EXPRESSIVE

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Speech Assessment

Speech difficulties stroke patients may have are difficulty:

Understanding speech (receptive deficit)
Expressing speech
Word finding difficulties
Slurred or garbled dysarthria speech

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Speech Assessment

Receptive Speech Testing

Ask the patient to:

Point to the ceiling
Make a fist
Close your eyes

Expressive Speech Testing

Show patient common objects and ask them to identify the object and what it does:

Key, Watch, Pen

Ask the patient to repeat:

You cannot treat an old dog new tricks

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MOVEMENT AND STRENGTH TESTING

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Movement Testing

Arm Motor Function

Leg Motor Function

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Strength Testing

Score	Strength
5	Able to move limb with full range of motion (ROM) with maximum resistance
4	Able to move limb with full ROM with moderate resistance
3	Able to move limb against gravity (i.e. off of bed) but unable to take resistance.
2	Able to move limb in bed with no gravity (i.e. unable to lift off of the bed)
1	Examiner palpates or visualizes a flicker of muscle contraction with no limb movement
0	No contraction in limb to command or stimulation

23

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Pronator Drift

Hand may pronate

Perform if suspected weakness

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NEGLECT

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TAP Test (Gaze or Shoulder Tap Test)

Does the patient have a forced gaze to one side usually opposite side of weakness ?
Are eyes unable to track pen to one side?
Have patient close eyes, can feel sensation on one arm or leg when both arms or legs are stimulated?

Shoulder Tap Test:

Stand on patient’s Left side and call name

Positive Test – Consistent gaze to RIGHT

Tap Left shoulder and call name

Positive Test – Patient does not quickly turn head and eyes to you (Neglect left side)

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VISUAL DISTURBANCE�VISUAL FIELD CUT�

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3

Each retina has 2 halves – a left half and a right half. The halves are referred to as a temporal half (next to your temple) and a nasal half (next to your nose).

Visual images are inverted as they pass through the lens. Therefore, in your right eye, the nasal retina sees the right half of the world, while the temporal retina sees the left half of the world.

If you drew a line through the world at your nose, they would see everything to the right of that line. That field of view is called the right hemifield. Each eye gets information from both hemifields.

Fibers from the nasal retinas cross over at the optic chiasm whereas the temporal retinas do not cross.

If there is damage to the visual pathway – different visual problems will occur.

The shaded areas in the circles (labeled 1 through 4) indicate where damage may occur and the chart to the right of the pathway indicates the resulting "blind" area (gray shading) of the visual field.

Damage at site #1: Monocular Blindness this would be like losing sight in the left eye. The entire left optic nerve would be cut and there would be a total loss of vision from the right eye.

Damage at site #2: partial damage to the left optic nerve. Here, information from the temporal field of both eyes are is lost. – Bitemporal Hemianopsia.

Damage at site #3: damage to the optic tract or the fiber tract from the lateral geniculate to the cortex can cause identical visual loss. In this case, loss of vision of the right side – Homonymous Hemianopsia

Damage at site #4: Lesions of left temporal lobe of the optic radiation on one side produces a loss of the upper, outer quadrant of vision on the contralateral side, known as homonymous superior quadrantanopsia .^[20] This is also known as pie in the sky disorder.^[2]

A lesion in the right parietal lobe cause inferior quadrantic hemianopia. It is also known as pie on the floor disorder.^[2]

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Confrontation

Have the patient look directly at your eye or nose and test each visual field by having the patient count how many fingers you are showing
Test one eye at a time.

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Questions

Rhonda McNicoll Whiteman

mcnicolr@hhsc.ca